You just never know how those Wall Street technology systems will do until there's a big spike in volume and a major sell-off.

The Dow Jones industrial average closed down 416.02 points, or more than 3 percent. The Nasdaq fell 96.66, or 3.86 percent. The culprit was the big decline in the Chinese stock market.

But that's not what has the blogosphere chattering. Around 3 p.m. The Dow plunged around 200 points in 2 minutes. As TheStreet.com's Jim Cramer says there wasn't time to panic. Some theories are being floated and all of them have heavy dose of technology involved. A few items that went wrong:

The Wall Street Journal's Scott Patterson reports that a tabulation delay by Dow Jones data systems led to a surge in order flows that couldn't be balanced. The Journal's MarketBeat blog notes that "just before 3 p.m., Dow Jones Indexes switched over to a backup system to calculate the average, which nearly instantly registered the huge move. The glitch wasn’t the cause of the decline, but it did cause the drop to register far more quickly than it otherwise would have."

This would explain some complaints by traders. RealMoney's Robert Marcin said in a post that "today's big problem was not the 3pm meltdown in the reported Indices, or the failure of the circuit breakers. It was the fact that the exchange bogged down the last half hour. I could not get trades executed during that period on the NYSE. Did anyone else have that happen?" MarketBeat said in a followup post that an NYSE spokeswoman wouldn't comment on technology issues.

A side note here is that the NYSE is finalizing a switch over to a mostly-electronic trading system. In a nutshell, the NYSE is phasing out much of the human touch involved in transactions. On days like this though, some humans halting trading may have helped.

Meanwhile, Keynote Systems said it "observed significant performance slowdowns for some of the nation’s leading online stock trading sites, most likely triggered by an increased volume in stock selling." Keynote added that the time it took to conduct trades on sites such as TD Ameritrade, Fidelity, Firstrade, Muriel Siebert, Schwab, ShareBuilder, TD Waterhouse and Wells Fargo began slowing about 1:30 p.m. ET.

Bottom line: Something is up, but the stories about the information technology amid today's correction are just starting to roll out.